APA102 2020 / dot star led's, pre-wired?

Hi all.
I'v recently started using the excellent APA102 2020 led's, required for their tiny size. I've wired 8 of them successfully, now installed into the project (model car) but due to the time it takes to wire them myself wondering if any specialist may sell these with wire tails already fitted?

Thanks for any info :wink:
Mark.

You can find Stripes of APA 102 of various lengths and densities(30/60/144LED/M), with or without a silicon tube and black or white PCB

image

The point would appear to be that he wants them wired without a PCB, just the fine wies or with a PCB no wider than the LED itself. :worried:

You can cut the individual leds (with the PCB indeed) in the middle of the connexions and get a "nice" soldering spot

Yes, as Paul mentioned, I need them wired direct to keep the footprint minimal as going inside small plastic pipes, I intend to use some on the strips but not the 5mm led's, only 2mm as space is real tight but if I could but them pre-wired would make the job a tad quicker.

Here's one of the 8 I wired;


Testing prior to installation;

& the pipes they go in, air intake's on 1/43 scale model car;

I've done another four this morning...before my iron's heating element burnt out :persevere:

nice soldering job ! not aware of any that would be pre-soldered with wires

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As I implied, unlikely to be a great demand for that particular format. One reason is that on such relatively flimsy wires, they can twist easily and not face in a consistent direction. OK if you are mounting each securely.

Speaking of twist, you should either keep the wires twisted together between the mounted LEDs, or run them through spaghetti. Allowing the wires to form loops may cause erratic operation.

The wires when bent 90 degrees maintain their position extremely well. I'm used this wire extensively - & thinner - from one of the companies I worked making NDT instrumentation, in R&D. We used to have some of our miniature sense-coils made in a specialist wiring company in Malaysia, this would have been perfect for them to handle.

Regarding twisting wires Paul, one should never twist clock & data wires together as this will enhance cross-talk leading to corrupt data, only balanced signal lines such as RS485 should be twisted. As only running 8 led's I've slowed the clock rate to negate any possible problems, my clock-pulse being of only ~20uS.


One of the two four-pipes;

Not quite 8-valve, but 8 bit :rofl:

Mark.

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Sounds like the quite useful "biceflux" enamelled wire - haven't seen that name for some decades now but used to be a "thing" - at soldering temperature the enamel readily melted and actually fluxed the soldering process.

Possibly so, but not relevant to this situation where there is only one data wire. Not sure about your comment regarding "slowing the clock" in this situation.

What is particularly amusing in regard to your need for minimal LED mounting on wires is that these arrived in the mail yesterday.

Not sure whether they are quite as small as you wanted and not practical to mount them "end-on" as you have, but does answer to your general description of minimal pre-wired LEDs.

Yet to try them out ...

Yes I've seen those type Paul. Strangely I have also yesterday received similar led's albeit just on the pcb's without wires, too big for my custom cars - the APA102 2020 is 2mm square & only just fits, yesterday's arrival are for use in a garden wall.

After wiring the 50 they'll be potted into a clear resin to fully seal, then embed into the wall's top layer of stone work via cement. This type are a bit 'fussy' on timing as the data-frame needs to adhere to a critical specification, whereas the APA102 type have separate Data & Clock input/output pins enabling a bit-bashing approach with code (I use a PIC on these) but the WS2812 type have some awesome Arduino libraries yielding excellent shows!


Using un-screened data wires that are in close proximity to clock lines can give problems, thus reducing my clock rate to minimise cross-talk, albeit i'm only running a few centimetre lines it's good practice.

Yes the wire is enameled wire, I used it extensively on my first cpu project (whilst at college in the 80's), a basic 8085 cpu based board.